Getting around Texas after flying into IAH is inconvenient, no doubt about it. Because the week that we were traveling bordered on a holiday, we were unable to get a one-way car rental from Enterprise in Houston to Galveston - in either direction. They say that it is up to the issuing agency whether they will allow one-way at an additional fee or not. TIP: Call multiple locations and ask their policy, because it can vary. In our case, it was almost cheaper to rent a car at the airport and pay for the car and parking at the port for the whole duration of the cruise, rather than using shuttle services. Ultimately, because we were a group of 8, we rented a car for our time in Houston, then returned it to the airport and used Super Shuttle to get back and forth from/to Bush Continental Airport, about 1 hr 45 min.
The port was crazy, but not terrible. Lines outside were not well controlled. Porters were bypassing the people waiting patiently in line to drop off luggage in favor of getting bags from people at their cars - because the people at the cars were tipping better. Tip: get it taken at curb if possible, wave $$ wherever you are. Also, when they send you luggage tags to print as part of your welcome packet - they mean it! If you don't print and attach them before you get to port, you have to wait in an additional line just to get the tags, before you can get in line for luggage, before you can get in line to enter the terminal, before you can get in line for security screening, before you can get in line to check in for the cruise. Also, in our family's case, their Platinum status didn't print on their boarding pass- which meant that they were not allowed to use the express line for premium members. Make sure you have proof of your membership status or the man controlling lines will treat you like a commoner.
The ship itself is an interesting mix of old and new. Our last cruise was on the Freedom of the Seas. After Navigator had a face lift this year, we were curious as to what to expect. The ship is comparable in the sense that it has ice skating, FlowRider, Adventure Ocean, the Promenade, rock climbing. Navigator does not have the Dreamworks Experience for kids. On Navigator, the pool area lacks the large kid-friendly shallow pools and the Promenade is not as large as on Freedom. In fact, the Promenade was beautiful, but kind of a bottleneck for the ship, especially with the super large Christmas tree in it. There are only a few shops, so don't plan on doing much shopping on board unless you want to purchase alcohol, perfume, or watches.
We had a balcony room and it was very very nice. Our family was in the next room and while our rooms didn't have an adjoining door, we were able to open the divider on the balcony.